The effects of mental illness on health are highly variable, depending on the mental illness involved and how well it is managed. Mental and physical health are closely linked, and mentally ill people are more at risk of problems like weight gain or loss, damage to the teeth, and gastrointestinal problems. These problems can be caused by medications, the underlying mental illness, or the inability to properly care for the body as a result of poorly controlled mental illness or bad living conditions, both potential problems for people with mental illness.
Some medications used to manage mental illness can have serious physical side effects and these effects of mental illness on health may not resolve when the medications are discontinued. Some examples include tardive dyskenesia, a movement disorder caused by some psychiatric medications, along with extreme weight gain or loss and other neurological problems. Patients may also develop issues like gastrointestinal problems caused by prolonged medication use.
Sometimes people with mental illness find it difficult to care for themselves. Poorly managed mental illness can make it harder to complete daily tasks and mentally ill people are more likely to be unemployed and living in poverty, making it difficult to get regular health care and stick with a health care regimen. This can result in effects of mental illness on health like poor nutrition, inadequate dental care, and not getting enough exercise. Alcoholism and its attendant physical health effects are more common in people with mental illness, and substance abuse can also be a problem.
The effects of mental illness on health can also include issues like damage to the teeth caused by grinding, either from anxiety or as a side effect of medication. Patients living in a constant state of stress can develop high blood pressure and heart problems, and people who are institutionalized may not get adequate exercise or health care, potentially leading to health problems. Homelessness caused by mental illness can add to physical stress, in addition to making it hard for patients to access health care reliably.
Some mental illnesses include physical expressions of ill health. Patients may self-harm, attempt suicide, or engage in activities like endless pacing or exercise, stressing and damaging the joints. These effects of mental illness on health can sometimes be managed with medications and therapy, and in other cases can only be reduced, but not entirely eliminated. Considering physical health issues when treating and working with mentally ill patients is an important part of providing complete patient care, as a feedback system can develop where poor physical health exacerbates mental illness or vice versa.